Apparatus for marking metal tubes during manufacture



March 17, 1936. FRANKLYN AL 2,034,614

APPARATUS FOR MARKING METAL TUBES DURING MANUFACTURE Filed March 16, 1934 I NVENTOHS FRANCIS A FRANKLYN EDWARD C. MCGREGOR By My ATTORNEYS Patented Mar. 17, 1936 UNlTED STATES FATE G'FFICE Francis Albert Franklyn and Edward Charles McGregor, London, England Application March 16, 1934, Serial No. 715,974 In Great Britain April 3, 1933 1 Claim.

The object of this invention is to provide a marking instrument associated with a die, former or shaper, whereby a metal tube can be automatically provided with a ridge or the like extending outside the surface of the tube and continuously along its length and such ridge continuously marked whilst the metal is passing through such die, former or shaper during manufacture by any known extrusion process or apparatus, rather than after the metal has passed the die, former or shaper or during ejection from a casting mould.

According to this invention, the wall of the die, which term is intended to include a former or shaper, is provided with a slot or recess opening into the interior thereof and running in line with the body of material being extruded, and in this slot or recess is positioned a freely rotating wheel or disc preferably mounted on an axle or shaft connected to the die, and provided with a recessed periphery having marking devices at the base of its peripheral recess, so that as the metal is being extruded through the die and between the ordinary mandrel and the inner wall of the die, the wheel or disc is revolved and the metal being then in a plastic condition will be pressed against and into the recessed edge of the wheel projecting inside the die, and revolve the wheel, and at the same time the wheel will form the ridge and effect the markings upon the tube completely along the length, the mandrel acting as a resistance during the marking.

The designs or configurations on the edge of the wheel may be of any character, but the edge of the wheel is provided with a recess having milled 5 or plain edges, and the recess is provided at its base with letters or figures which are preferably sunken, so that a ridge or extension having raised letters or figures or both will be imparted to the tube, wholly along its length at one time.

The wheel or disc closely fits the slot in the die, and the usual mandrel is positioned within the die, such mandrel providing a resistance to the action of the wheel and preserving the shape of the tube.

The invention will be clearly understood from 5 the following description aided by the annexed drawing.

Figure 1 is a part sectional elevation of sufficient structure of a known tube making apparatus to explain the invention but it must be understood 5 that the invention can be combined with any apparatus where a tube is made by extrusion.

Figure 2 is a longitudinal section, enlarged, of the die and a portion of its holder, and Figure 3 a section on the lines HI, III of Figure 2.

Figure 4 is a plan view of a marking wheel or disc having a sunken recess with projecting edges, the recess being provided at its base with letters or figures of a sunken character, so as to form raised letters or figures on a ridge or extension along the tube.

Figure 5 is a section of a part of a tube showing the ridge or extension having the raised lettering and figuring produced by the marking wheel shown in Fig. 4.

As shown on the annexed drawing, the die A is provided at its upper end with a circular recess B, such recess being fiat and of a size to fit the marking wheel or disc, and such circular recess B is open to inside the die, and at the top inside as shown, and within the recess B is mounted the marking wheel or disc C carried by an axle or shaft D positioned in holes or bearings bored transversely of the die A. Such marking wheel or disc C is provided with a recess around its periphery having projecting side edges, the base of the recess having marking devices E, as previously explained with regard to Figures 4 and 5.

In the form of apparatus shown on the drawing, the die A is connected to a tubular die holder F depending from the top plate G of a frame H, H, and on this frame H, H, is positioned by arms I, I, the vessel J containing the semi-molten metal, such vessel carrying the mandrel K, and the vessel J is lifted by the hydraulic press L, and in so doing the mandrel K will enter the die A and the semimolten metal will be passed up between the mandrel K and die A and its holder F in a manner well known, and the metal now in tubular form will act upon the marking wheel or disc C and in so doing will revolve same and in consequence of the pressure imparted to it, the metal will be formed with a ridge which will receive from the marking wheel or disc C an impression or otherwise of the characters or markings on the periphcry of the disc, the mandrel K acting as a resistance to the action of the marking wheel and thereby allowing a continuous rib with markings thereon to be produced without distorting or injuring the tube, this ridging and marking continuing until the operation of extrusion ceases, and since the metal at the time of marking is in a suitable plastic condition, it will retain the markings.

Although we have shown and described the marking wheel or disc as being applied to a certain class of apparatus and positioned within the die, it must be understood that the invention is applicable to other classes of apparatus where tubes are made by extrusion, the marking wheel or disc being mounted relatively to the die where the marking can be efiected as the extrusion process continues, and the marking wheel being opposite to the mandrel so that the latter will act to sustain the pressure applied to the tube by the marking wheel and thus insure efiective marking thereof.

What we do claim as our invention and desire to obtain by Letters Patent is In apparatus for marking tubes during manufacture thereof by extrusion, the combination of a die having a passageway therein and a slot in a side wall of said passageway, a mandrel movable in said passageway, means for extruding material through said passageway around said mandrel to form a tube, and a marking wheel having a recess and projecting side edges extending around its periphery and provided at the base of its peripheral recess with marking devices, said marking wheel being mounted rotatably in said slot with its recessed periphery presented to said passageway in the die opposite to the path of movement of the mandrel therein to press against the material between it and the mandrel during extrusion through said passageway to form a longitudinal m ridge projecting from the surface of the tube bearing impressions of said marking devices.

FRANCIS ALBERT FRANKLYN. EDWARD CHARLES MCGREGOR. 

